There is a dearth of empirical studies of the value of professional development from the perspectives of heads and teachers in Kenya. The book is a study of teacher professional development needs, the consequences of particular levels of professional development, the perceptions of teachers of their own effectiveness and the main barriers to improving the professional development of teachers. An evaluation of the effectiveness of CPD in the framework of various available approaches to the evaluation of CPD is analysed in the book. It shows that head teachers and teachers both felt the need for CPD for teachers but that this was expressed much more strongly by the heads than by the teachers. The area in which this need was expressed most strongly was in relation to external pressures on schools for new curriculum initiatives and examination performance. In general, the concludes that there is a felt need for CPD and its value for teachers and schools and it confirms the association between teacher quality and pupil examination outcomes.